Bluetooth audio streaming passthrough

ABSTRACT

A Bluetooth audio streaming passthrough, and a method for transmitting an audio stream over a Bluetooth communication link and disclosed. The method is carried out by a source device. An audio codec configuration and a sampling rate of the audio stream are received, the audio stream coming from a streaming application running on the source device. A Bluetooth audio stream between the source device and a sink device is configured using the received audio codec configuration and sampling rate. The first audio stream is received from the streaming application. The received first audio stream is packetized into the Bluetooth audio stream. The Bluetooth audio stream is transmitted to the sink device over the Bluetooth communication link, including the packetized received audio stream.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of European Application No.EP19306521.6, filed on Nov. 26, 2019, which is incorporated by referenceherein in its entirety for all purposes.

BACKGROUND

Bluetooth defines a communication standard for transmitting andreceiving audio data wirelessly over distances which are typicallylimited up to 10 meters and using radio waves with a frequency comprisedin the Ultra High Frequency band. This standard makes Bluetooth devicesvery popular among customers due to their portability, and inparticular, for short-range applications.

The audio quality of the transmitted and received data depends mainly ondigital audio encoders and decoders, called codecs, which are used totransfer data to Bluetooth audio output devices like headphones orloudspeakers. The use of standard Bluetooth codecs, namely, thelow-complexity subband codec called SBC, is necessary as it is designedto provide a reasonably good audio quality at medium bit rates whilekeeping low computational complexity. Further, SBC supports mono andstereo streams with sampling frequencies up to 48 kHz while bitrates areusually being set up to 193 kbit/s and 328 kbit/s for mono andjoint-stereo streams, respectively.

In view of improving the quality of transmitted and received audio data,a current trend is to propose codecs requiring increasingly largebandwidth usage, such as the APTX audio codec compression algorithm orthe LDAC audio hybrid coding technology, which allows streaming audioover Bluetooth connections with bitrates up to 352 and 990 kbit/s,respectively.

Because of the need for lossy compression due to limited bandwidth, suchcodecs are being developed so as to limit the audio quality loss whenusing standard Bluetooth protocols and codecs, such as SBC.

However, the quality of an audio stream is not necessarily improved byusing codecs which have a higher bandwidth usage, since achieving such aquality depends on the different coding, decoding, mixing and samplingprocesses which are used by audio devices for transmitting audiostreams. This is true, in particular, for source devices such assmartphones and sink devices such as wireless headphones or speakers,when using the Bluetooth standard.

Moreover, the streaming applications used by the current audio listeningdevices rely on their own encoding format, which has a highercompression rate and better algorithms than the standard Bluetoothcodecs such as SBC. This also implies that audio data being streamedbetween a source and a sink device suffers multiple decoding, encodingand resampling processes, resulting in possibly significant qualityloss.

SUMMARY

The present disclosure relates to the field of audio streaming.Specifically, the present disclosure relates to methods and devices fortransmitting an audio data stream using a Bluetooth communication link.

An object of the present disclosure is to provide methods and devicesfor improving the quality and the latency of an audio stream, andspecifically, of an audio stream transmitted by Bluetooth.

To address at least some of the aforementioned issues, a first object ofthe disclosure relates to a method for transmitting an audio stream overa Bluetooth communication link, the method being carried out by a sourcedevice and comprising:

receiving an audio codec configuration and a sampling rate of the audiostream, said audio stream coming from a streaming application running onthe source device;

configuring a Bluetooth audio stream between the source device and asink device using the received audio codec configuration and samplingrate;

receiving the first audio stream from the streaming application;

packetizing the received first audio stream into said Bluetooth audiostream; and

transmitting the Bluetooth audio stream to the sink device over theBluetooth communication link, the transmitted Bluetooth audio streamcomprising the packetized received audio stream.

Herein, Bluetooth refers to any version of the Bluetooth protocol,including existing and future versions. Currently, version 5.1 ofBluetooth comprises Basic Rate/Enhanced Data Rate protocol, also calledBR/EDR protocol or Bluetooth classic protocol, and Bluetooth Low Energyprotocol, also called BLE protocol.

Herein, a communication link designates a wireless communication betweentwo devices. Further, a Bluetooth communication link is configured toinclude a plurality of Bluetooth physical links, for instance between agiven source device and a given sink device, such as a smartphone. ABluetooth communication link may comprise different types of links, suchas a point-to-point connection or a one-way link.

Herein, packetizing designates transforming audio data into multipleaudio data packets. Such audio data packets correspond to a given numberof bytes.

Herein, a codec is a hardware or a software component configured forencoding and/or decoding digital data stream or a signal.

Herein, an audio codec configuration is a configuration which includesinformation such as a type of codec, a bitrate, i.e. a rate at whichbits can be transferred from one location to another, and acorresponding integer size such as 16 bits or 24 bits. Types of codeccomprise SBC, AAC, MP3, APT-X, LDAC, LHDC, Vorbis, Opus or LC3 codecs.

Herein, the streaming application is preferably an audio application ora gaming application which is configured to stream audio and/or videodata.

The method according to the first object allows transmitting an audiostream over a Bluetooth communication link with reduced quality loss andlower latency. Indeed, the methods of the background art generallyrequire source device and/or sink devices to perform an encoding, adecoding, and resampling or a mixing of the audio stream, whichsystematically results in a quality loss or in an increase of thelatency.

Herein, an audio application can be any application providing a digitalmusic, an access to an audio content or a podcast streaming service,such as a cloud-based streaming service or in general.

This allows providing a Bluetooth audio streaming passthrough. Namely,when the streaming application comprises a gaming application, thisallows transmitting and streaming corresponding audio data over aBluetooth communication link with a low latency, by streaming directlyfrom the gaming application and bypassing the audio server to improvethe latency.

Herein, an audio codec configuration can be empty. Typically, an emptyaudio codec configuration refers to non-encoded audio data, such as apulse-code modulation, called PCM, or an analog audio signal whichcorresponds to a PCM audio codec configuration.

In an embodiment, the Bluetooth communication link is pre-established,that is, a Bluetooth communication link which is established between thesource device and the sink device during a preliminary step whichprecedes the transmitting of the Bluetooth audio stream to the sinkdevice.

In a specific embodiment, the receiving of the audio stream from thestreaming application is carried out upon receipt of an unmodifiedbitstream from the streaming application.

Herein, a bitstream is a sequence of bits. Packets resulting frompacketizing audio data can be grouped, encoded or decoded intocontiguous pages of structured bitstream data, said contiguous pagesbeing called logical bitstreams.

Herein, several logical bitstreams can be combined into a singlephysical bitstream. If a physical bitstream comprises more than onelogical bitstream, such logical bitstreams are said to be “wrapped” inthe physical bitstream. Unwrapping said logical bitstreams from thephysical bitstream can be performed by decoding, although a completedecoding is not necessarily required for extracting multiple logicalbitstreams.

Herein, an unmodified bitstream is a bitstream that is transmitted assuch and is not resampled, for instance by an audio server locatedbetween the audio application and the Bluetooth stack of the sourcedevice.

In a specific embodiment, the method further comprises:

receiving at least one other audio stream, called second audio stream,from an audio server; and

transmitting said received second audio stream to the sink device overthe Bluetooth communication link.

Herein, an audio server is any platform configured to manage and/orshare audio resources or audio flows with other systems, said systemscomprising, in particular, the source device and the sink device. Forinstance, said audio resources or audio flows comprise music from anaudio application, sound notifications from a social media, sound from aclock alarm from a scheduling application, etc.

Herein, an audio server can comprise an audio hardware interface, anoperating system, a computer, an electronic circuit or any kind ofcomputer-readable medium on which audio data can be stored or that canreceive and send a stream of audio data. Said audio server can beconnected to a network like the Internet.

This provides a hybrid streaming method with two audio streams, said twoaudio streams being encapsulated in a single Bluetooth audio stream.

This allows the method of the first object to generate an alternativepath for transmitting and streaming audio data, said path bypassingpossible audio servers that are required in methods of the backgroundart. Therefore, this allows avoiding performing coding, decoding, mixingor resampling implying quality loss on a receiving end of the Bluetoothcommunication link.

This also allows transmitting the audio streams with reduced qualityloss and lower latency compared to known methods involving receiving andtransmitting an audio stream from an audio server, since said methodsrequire such an audio stream to be mixed with the audio stream comingfrom the streaming application, resulting in quality loss. Moreover,these methods also require the audio server to perform a mixing or aresampling of the audio streams using the sampling rate of the audioserver or of the sink device, which results in a loss of quality and mayalso increase the latency.

In a specific embodiment, the Bluetooth audio stream is of amulti-contribution type, the method further comprising packetizing thereceived second audio stream into the Bluetooth audio stream using anaudio codec configuration and a sampling rate of the second audiostream.

This provides a hybrid streaming method with two audio streams, said twoaudio streams being encapsulated in two Bluetooth audio streams on asingle Bluetooth communication link.

Herein, a Bluetooth audio stream being of a multi-contribution typeimplies that the audio codec configuration (or the sampling rate) isused in a non-exclusive way. In other words, the audio codecconfigurations (or the sampling rates) of both the first audio streamand the second audio stream are used to configure the Bluetooth audiostream, which then corresponds to a multi-contribution type Bluetoothaudio stream.

In a specific embodiment, the method further comprises:

receiving, by the sink device, a plurality of Bluetooth audio streamstransmitted by the source device;

mixing the plurality of Bluetooth audio streams into a mixed audiostream; and

rendering the mixed audio stream in the sink device.

This allows improving the quality and/or the latency of multiple audiostreams on the receiving end of the Bluetooth communication link.

In a specific embodiment, the method further comprises wrapping theaudio stream received from the streaming application and/or the receivedsecond audio stream into a container, said container being placed intothe Bluetooth audio stream.

This allows encapsulating multiple audio streams in a single container,so that it is possible to transmit said streams in a same packet even ifthey correspond to different audio codec configurations and/or samplingrates. In other words, this provides a hybrid streaming method with twoaudio streams, said two audio streams being encapsulated in a singlecontainer which is sent from the source device in a single container.

In embodiments, the streaming application and the audio server usedifferent codecs, and therefore, different audio codec configurationsand different sampling rates. For instance, the application may use ahigh-quality codec for audio streaming and the audio server may use alow-quality codec for notifications.

For instance, an Ogg stream can be used to encapsulate one or severallogical bitstreams created by one or several encoders of an audioserver. Once encoded, an audio server logical bitstream can be wrappedinto the container with the application logical bitstream, both logicalbitstreams being transmitted to the sink device using a same packet. Thesink device can then unwrap the two logical bitstreams, decode themseparately using their respective codecs and mix them into a single rawstream to be output.

Herein, a container is an entity defining a media payload format. Anaudio container, which defines an audio payload format, can beassociated with one or multiple codecs. For instance, a LATM containercan be associated with an AAC codec, an Ogg container can be associatedwith a Vorbis or an Opus container.

In a specific embodiment, the container is an Ogg-Vorbis container.

In a specific embodiment, the audio stream received from the streamingapplication, called first audio stream, and the second audio stream arewrapped into the container, the packetizing of said first and secondaudio streams into the Bluetooth audio stream being carried out usingthe first and second wrapped audio streams.

In a specific embodiment, the first audio stream or the second audiostream is a Vorbis encoded stream, or the first audio stream and thesecond audio streams are Vorbis encoded streams.

In an embodiment, at least two Bluetooth logical links are used fortransmitting audio streams.

This provides a hybrid streaming method for transmitting at least twoaudio streams. In particular, two audio streams are encapsulated in twoBluetooth audio streams, to be transmitted over the Bluetoothcommunication link.

This allows transmitting audio streams with a higher flexibility, sinceat least two Bluetooth logical links can be used. Even if there isalready an established Bluetooth audio stream bypassing the audio serveron a first Bluetooth logical link, a second Bluetooth audio stream canbe used on a second Bluetooth logical link, e.g. for collectingnotifications arising from another application running on the sourcedevice. Thus, this allows two Bluetooth audio streams to be transmittedon a same logical channel, or on two different logical channels.

For instance, if the streaming application is a gaming application, saidgaming application can stream audio data directly towards a Bluetoothstack that the source device comprises. However, there is moreflexibility in using at least two Bluetooth audio streams on twodifferent Bluetooth logical links, since at least one Bluetooth audiostream can be used to render high quality audio from the gamingapplication, and at least another Bluetooth audio stream can be used torender sound from another source, such as sound notifications from asocial media application running on the source device or coming from theaudio server. The two logical links are either using the same Bluetoothphysical link or two different ones.

In a specific embodiment, the method further comprises:

packetizing the received second audio stream into another Bluetoothaudio stream, called second Bluetooth audio stream, said secondBluetooth audio stream being distinct from the Bluetooth audio streamconfigured between the source device and the sink device, called firstBluetooth audio stream, and

transmitting said second Bluetooth audio stream to the sink device overthe Bluetooth communication link, the second Bluetooth audio streambeing multiplexed with said first Bluetooth audio stream.

Herein, multiplexing is carried out using one or more protocols, such asan AVDTP protocol or any other protocol adapted for transmitting anaudio stream over a Bluetooth communication link.

In a specific embodiment, the first Bluetooth audio stream or the secondBluetooth audio stream is transmitted over a BR/EDR link of theBluetooth communication link, or the first Bluetooth audio stream andthe second Bluetooth audio streams are transmitted over a BR/EDR link ofthe Bluetooth communication link.

In a specific embodiment, the second Bluetooth audio stream istransmitted over a BLE link of the Bluetooth communication link.

In a specific embodiment, the transmitting of the Bluetooth audio streamis performed upon a successful negotiation, with the sink device, of theaudio codec configuration and of the sampling rate.

This allows ensuring that the sink device supports both the audio codecconfiguration and the sampling rate. This also allows the streamingapplication checking itself whether the sink device can support or notthe native codec and the native sampling rate of the streamingapplication.

According to a second object, the disclosure relates to a method forreceiving a Bluetooth audio stream over a Bluetooth communication link,the method being carried out by a sink device, wherein the methodcomprises:

receiving, a plurality of Bluetooth audio streams transmitted by asource device over the Bluetooth communication link;

mixing the plurality of received Bluetooth audio streams into a mixedaudio stream; and

rendering the mixed audio stream.

In an embodiment of the method of the second object, at least one firstBluetooth audio stream among said received plurality of Bluetooth audiostreams comprises a packetized audio stream, the packetizing of saidaudio stream into the first Bluetooth audio stream being performed bythe source device, the first Bluetooth audio stream being configuredbetween the source device and the sink device by the source device usingan audio codec configuration and a sampling rate of a first audiostream, said audio codec configuration and said sampling rate beingreceived by the source device, said first audio stream coming from astreaming application running on the source device.

In an embodiment of the method of the second object, the transmitting ofthe first Bluetooth audio stream is performed by the source device upona successful negotiation, with the sink device, of the audio codecconfiguration and of the sampling rate.

In an embodiment, the method of the second object further comprises:

receiving, from the source device, at least a second audio stream overthe Bluetooth communication link,

said second audio stream being received by the source device from anaudio server, said second audio stream being different from the firstaudio stream.

In an embodiment, the method of the second object further comprises:

receiving, from the source device, a second Bluetooth audio stream overthe Bluetooth communication link,

the second Bluetooth audio stream being multiplexed with the firstBluetooth audio stream, the received second audio stream beingpacketized by the source device into the second Bluetooth audio stream,said second Bluetooth audio stream being distinct from the firstBluetooth audio stream.

According to a third object, the disclosure relates to a computerprogram product comprising a computer readable medium having storedthereon computer program instructions loadable into a computing deviceand adapted to—when loaded into and executed by said computingdevice—cause the computing device to perform the steps of a methodaccording to anyone of the previous embodiments.

According to a fourth object, the disclosure relates to a source devicefor transmitting an audio stream over a Bluetooth communication link,said source device being configured to:

receive an audio codec configuration and a sampling rate of the audiostream of a streaming application running on the source device;

configure a Bluetooth audio stream between the source device and a sinkdevice, using the received audio codec configuration and sampling rate;

receive the audio stream from the streaming application;

packetize the received audio stream into said Bluetooth audio stream;and

transmit the Bluetooth audio stream to the sink device, the Bluetoothaudio stream comprising the packetized received audio stream.

According to a fifth object, the disclosure relates to a sink device forreceiving a Bluetooth audio stream over a Bluetooth communication link,said sink device being configured to:

receive a plurality of Bluetooth audio streams transmitted by a sourcedevice over the Bluetooth communication link;

mix the plurality of Bluetooth audio streams into a mixed audio stream;and

render the mixed audio stream at the sink device.

In an embodiment of the sink device of the fifth object, at least oneBluetooth audio stream among said received plurality of Bluetooth audiostreams comprises a packetized audio stream, the packetizing of saidaudio stream into said at least one Bluetooth audio stream beingperformed by the source device, the at least one Bluetooth audio streambeing configured between the source device and the sink device by thesource device using an audio codec configuration and a sampling rate ofa first audio stream, said audio codec configuration and said samplingrate being received by the source device, said first audio stream comingfrom a streaming application running on the source device.

According to a sixth object, the disclosure relates to a system fortransmitting and receiving a Bluetooth audio stream over a Bluetoothcommunication link, said system comprising a source device according tothe fourth object and a sink device according to the fifth object.

Other features, details and advantages of the objects of the disclosurewill be apparent from the following detailed description given by way ofnon-limiting example, with reference to the accompanying drawings, asdescribed hereafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of method steps according to a firstembodiment of the disclosure.

FIG. 2 illustrates a flowchart of method steps according to a firstembodiment of the disclosure.

FIG. 3 illustrates an example of structure of a Bluetooth data packetaccording to the disclosure.

FIG. 4 illustrates method steps according to a second embodiment of thedisclosure.

FIG. 5 illustrates a flowchart of method steps according to a thirdembodiment of the disclosure.

FIG. 6 illustrates method steps according to the third embodiment of thedisclosure.

FIG. 7 illustrates a Bluetooth communication link according to the thirdembodiment of the disclosure.

FIG. 8 illustrates a flowchart of method steps according to a fourthembodiment of the disclosure.

FIG. 9 illustrates method steps according to the fourth embodiment ofthe disclosure.

FIG. 10 illustrates a Bluetooth communication link according to thefourth embodiment of the disclosure.

FIG. 11 illustrates a flowchart of method steps according to a fifthembodiment of the disclosure.

FIG. 12 illustrates Bluetooth communication links according to the fifthembodiment of the disclosure.

FIG. 13 illustrates a flowchart of method steps according to a sixthembodiment of the disclosure.

FIG. 14 illustrates method steps according to the sixth embodiment ofthe disclosure.

FIG. 15 illustrates a Bluetooth communication link according to thesixth embodiment of the disclosure.

FIG. 16 illustrates the structure of a circuit according to embodimentsof the disclosure.

DETAILED DESCRIPTION

Figures and the following detailed description contain, essentially,some exact elements. They can be used to enhance the understanding ofthe disclosure and, also, to define the disclosure if necessary.

FIG. 1 illustrates simplified method steps for transmitting an audiostream over a Bluetooth communication link, according to a firstembodiment of the disclosure.

A method according to said first embodiment comprises encoding audiodata AD as an encoded audio bitstream, said encoded audio bitstreambeing provided by an audio streaming application 40 to a sink device 20.

For instance, said audio streaming application is an audio applicationor a gaming application (e.g. on a remote server). For instance, saidsink device 20 is a loudspeaker or wearable headphones.

The audio data AD is provided to the sink device 20 over a Bluetoothstack BS, said Bluetooth stack BS being included in a source device 10,e.g. a smartphone.

Herein, a Bluetooth stack BS refers to an implementation of a Bluetoothprotocol stack, such as an embedded system implementation of the sourcedevice 10.

In an embodiment, the Bluetooth stack BS comprises a microcontrollerand/or a chipset with an operating system and is configured to supportvarious protocols such as L2CAP and AVDTP protocols, as is describedhereafter.

During step S1, the audio streaming application 40 transmits the audiodata AD to the source device 10 and said audio data is sent by thesource device 10 directly to its Bluetooth stack BS, withoutmodification of the audio data (i.e. without going through the audioserver of the source device).

This allows the streaming application of the audio streaming application40 to provide the audio data AD to the Bluetooth stack BS withoutrequiring decoding, encoding and/or (re)sampling by an intermediarydevice/server.

During step S2, the audio data AD received by the Bluetooth stack BS ispacketized into a packetized audio data PAD.

In an embodiment, at least one of the audio data AD and the packetizedaudio data PAD is a Bluetooth data packet, which can be transmittedusing a Bluetooth wireless audio link.

During step S3, the source device 10 transmits the packetized audio dataPAD to the sink device 20, said transmitting being carried out over oneor more Bluetooth audio streams.

During step S4, the sink device 20 decodes the received packetized audiodata PAD and sends the decoded data under the form of an audio outputOUT, for instance, a PCM signal or broadcast music.

FIG. 2 illustrates a flowchart of method steps according to the firstembodiment of the disclosure.

Upon receipt of audio data AD1, and in particular of an encoded audiobitstream, through an input IN of the source device 10, the streamingapplication 40 directly provides said audio data AD1 to the Bluetoothstack BS of the source device 10.

This allows bypassing any mixing, resampling and/or encoding step thatcould be carried out over AD1 by the source device 10 or by an audioserver 30 which could be comprised in the source device 10.

The audio data AD1 is configured by the source device 10 using the audiocodec configuration and the sampling rate of the audio stream of thestreaming application 40 running on the source device 10. Prior to theexecution of this step, the source device can receive the audio codecconfiguration and sampling rate of the audio stream from the streamingapplication when the streaming application first requests the opening ofa new audio stream, or through other means. While providing the audiodata AD1 to the Bluetooth stack BS, the Bluetooth stack BS packetizes itand transmits it to a third-party device, and here specifically, to thesink device 20.

In particular, the audio data AD1 is packetized into a configuredBluetooth audio stream using the audio codec configuration and thesampling rate of the audio stream of the streaming application 40.

Preferably, the packetized audio data or the configured Bluetooth audiostream is transmitted using a pre-established link, here a Bluetoothcommunication link L1. The Bluetooth communication link L1 can includeone or more Bluetooth physical links and Bluetooth logical links,established or pre-established between the source device 10 and the sinkdevice 20.

Upon receipt, the packetized audio data is decoded by the sink device20. Subsequently, the decoded packet can be broadcast or streamedthrough an output OUT of the sink device 20.

This allows avoiding lossy transmission and/or compression during any ofthe aforementioned steps. In particular, this allows bypassing the useof an audio server.

FIG. 3 illustrates an example of a structure of a Bluetooth data packetaccording to the disclosure, and more specifically, an example of such astructure for transmitting data using a Bluetooth communication link.

As illustrated, a Bluetooth data packet BTDP comprises several layers,packets, packet data units, frames and/or bitstreams. In particular, theBluetooth data packet BTDP comprises a logical link control andadaptation protocol, called L2CAP, corresponding to a protocol dataunit, called PDU. The L2CAP defines a protocol layer of the Bluetoothdata packet BTDP for exchanging data between two channel identifiers,called CIDs.

Advantageously, the L2CAP also defines a link manager layer whichimplements one or more Bluetooth transport protocols. The L2CAP furtherenables segmenting data packets, assembling data packets, reassemblingdata packets, and/or multiplexing.

The L2CAP protocol further allows establishing a logical link between aBluetooth chip of a device. The parameters of the L2CAP protocol maydepend on the features of the source device, such as its ability tosupport other protocols, etc.

Preferably, the L2CAP protocol comprises an Audio/Video DistributionTransport Protocol, called AVDTP, which is a Bluetooth audio datatransport protocol. An AVDTP protocol defines binary transactionsbetween several Bluetooth devices and allows establishing an audiostream and/or a video stream between two stream endpoints, called SEPs.

Advantageously, the AVDTP protocol is configured for setting up a streamand for streaming an audio stream using the L2CAP protocol. The AVDTPprotocol further allows a negotiation of the stream parameters and canmanage an audio stream by itself.

The AVDTP protocol and the L2CAP protocol enable the exchange of dataover a Bluetooth communication link, for instance between a sourcedevice and a sink device.

As illustrated, the AVDTP protocol comprises a media payload, calledcontainer CT, the container CT itself comprising an encoded frame ENC.

Preferably, the container CT comprises a media payload header and one ormore encoded frames.

Herein, the container CT defines a physical bitstream and at least oneencoded frame ENC defines a logical bitstream. The physical bitstreammay contain both encoded data and associated metadata.

Herein, at least one encoded frame corresponds to audio data which isencoded using an Advanced Audio Coding codec, or AAC codec. The AACcodec is an audio coding standard for lossy digital audio compression,which advantageously results in a better sound quality than what can beachieved with a MP3 codec at the same bit rate.

FIG. 4 illustrates method steps according to a second embodiment of thedisclosure.

The method steps of the second embodiment allow transmitting an audiostream over a Bluetooth communication link similarly to the firstembodiment, but so that said transmitting is performed upon a successfulnegotiation of the audio codec configuration and of the sampling rate.

During step S10, a Bluetooth communication link is open, that is,established between the source device 10 and the sink device 20. When astreaming application running on the source device 10 is ready to sendaudio data, said streaming application can request the opening of a newstream. Alternatively, or simultaneously, a reconfiguration of anexisting stream can be requested when opening the Bluetoothcommunication link. In either case, this process can include the sourcedevice receiving an audio codec configuration and a sampling rate forthe new or reconfigured stream from the streaming application.

While establishing the Bluetooth communication link, an optionalnegotiation phase can be carried out during a step S15.

Said negotiation phase comprises checking if one or more parameters ofthe stream are supported by the sink device 20. For instance, said oneor more parameters are passed as arguments of the stream being opened orreconfigured.

Said one or more parameters comprise at least one audio codecconfiguration and one sampling rate of the audio stream of the streamingapplication running on the source device 10. The required codec and thesampling rate can be passed as an argument of the stream.

During step S15, and if the sink device 20 does not support the audiocodec configuration and/or the sampling rate, the underlying request foropening the new stream of for reconfiguring the existing stream can berejected during a step S20.

During step S15, and if the sink device 20 supports the codec and thesampling rate, the request is accepted and the source device 10 carriesout the following steps, including step S40, as described hereafter.

During step S40, a configuration of the new stream is carried out or, ifappropriate, a reconfiguration of the existing stream, using the one ormore parameters. In particular, said configuration is carried out usingthe audio codec configuration and the sampling rate of the audio streamof the streaming application.

Preferably, a Host Controller Interface, called HCI, of the sourcedevice 10 is used to carry out step S40.

Herein, an HCI is an optional standard interface between a Controllersubsystem and a Host subsystem. In Bluetooth devices having simplefunctionality (e.g., headsets), the host and the controller can beimplemented on a same microprocessor or as an internal softwareinterface. The HCI of the source device 10 can perform the configurationor the reconfiguration of the stream during step S40, which is forinstance a Bluetooth A2DP stream.

During step S50, the source device 10 receives the audio stream from thestreaming application.

During step S60, the source device packetizes the received audio streaminto the Bluetooth audio stream which has been configured during stepS40 using the audio codec configuration and the sampling rate.

During step S70, the source device 10 transmits the Bluetooth audiostream comprising the packetized received audio stream to the sinkdevice 20.

FIG. 5 illustrates a flowchart of method steps according to a thirdembodiment of the disclosure. In this third embodiment, not only theaudio data AD1 is received by the Bluetooth stack BS from the input INof the source device 10, but also audio data AD2 sent by an audio server30 comprised in the source device 10 (said audio data AD2 may be forinstance of system audio notification).

Both AD1 and AD2 are then packetized into a configured Bluetooth audiostream using the audio codec configuration and the sampling rate of theaudio stream of the streaming application 40.

The configured Bluetooth audio stream is then transmitted from thesource device 10 to the sink device 20 using an established Bluetoothlink L1, and both packetized audio data AD1 and AD2 are unpacketized bythe sink device 20, and optionally, decoded in one or more distinctsteps before being rendered, broadcast or further streamed through theoutput OUT.

If, after the unpacketizing, the audio data is decoded during separatesteps by the sink device 20, the decoded data can be subsequently mixedor multiplexed before being rendered, broadcast or further streamedthrough the output OUT (the Bluetooth audio stream may then additionallycomprise information on the way to mix data, e.g. the respectivepercentage/value of volume for each audio data on the sink device side).

This allows combining multiple audio sources. Advantageously, and forinstance, this allows receiving audio notifications, e.g. notificationsfrom a social media application installed on the source device 10, whilesimultaneously listening to a music file provided by a streamingapplication 40 running on the source device 10.

Preferably, when more than one or more than two audio sources arepresent, the corresponding audio data may be mixed in at least one audioserver and resampled using the sampling rate of the sink device 20,which corresponds to the sampling rate of the streaming application 40when an existing stream has been reconfigured.

In other words, the shown embodiment allows several audio sources,including the streaming application 40 and at least one audio server 30,to use a simplified audio link path for the streaming application.

FIG. 6 illustrates method steps for transmitting an audio stream over aBluetooth communication link, according to the third embodiment of thedisclosure.

In particular, the method steps of the third embodiment allowtransmitting an audio stream over a Bluetooth communication linksimilarly to the first and second embodiments, except that the receptionstep S50 is replaced by two steps S51 and S52 which are either carriedout simultaneously or successively. Step S51 comprises receiving, by thesource device 10, first audio data AD1 from the streaming application 40and step S52 comprises receiving, by the source device 10, second audiodata AD2 from the audio server 30.

FIG. 7 illustrates a Bluetooth communication link for carrying out thethird embodiment of the disclosure.

In particular, a Bluetooth audio stream BTSTRM, corresponding to thepacketization of two audio streams, is transmitted from the sourcedevice 10 to the sink device 20, said Bluetooth audio stream BTSTRMcomprising a first contribution ASTRM1 and a second contribution ASTRM2.Preferably; said first contribution ASTRM1 is an audio stream providedby the streaming application running on the source device 10 and saidsecond contribution ASTRM2 is an audio stream provided by an audioserver.

Preferably, the Bluetooth audio stream BTSTRM is an A2DP Bluetooth audiostream.

The Bluetooth audio stream BTSTRM is enabled by a logical link LL1, andpreferably an ACLU logical link.

Herein, a logical link is a link which defines what type of informationis carried by the Bluetooth audio stream BTSTRM. For instance, saidlogical link carries control data or user data, said user data beingsubdivided into framed data and unframed data.

Preferably, the logical link LL1 is carried by a logical transport LT1,and preferably an ACL logical transport.

Herein, a logical transport is a wireless transport which defines whattype of characteristics is carried by the stream. Moreover, a logicaltransport can support one or more logical links and said characteristicscomprise casting type, scheduling behavior, acknowledgment/repeatmechanisms, flow control, and sequence numbering, among others. Inparticular, Bluetooth logical transports can carry different types oflogical links, depending on the type of logical transport, and whenseveral Bluetooth logical links are used, said Bluetooth logical linkscan be multiplexed onto the same logical transport.

Examples of logical transports include asynchronous connection-oriented,or ACL, synchronous connection-oriented, or SCO, extended synchronousconnection-oriented, or eSCO, active slave broadcast, or ASB,connectionless slave broadcast, or CSB, LE asynchronous connection, orLE ACL, LE advertising broadcast, or ADVB, LE periodic advertisingbroadcast, or PADVB, transports. Other examples include LE connectedisochronous and broadcast isochronous streams.

The Bluetooth audio stream BTSTRM, the logical link LL1 and the logicaltransport LT1 define a communication link. Thus, the communication linkis defined by at least one physical link between two devices. Further,said communication link includes one or more physical links, and definesthe wireless communication between two devices and, in the present case,between the source device 10 and the sink device 20.

The Bluetooth audio stream BTSTRM, the logical link LL1 and the logicaltransport LT1 define a physical link PL1, such as a BR/EDR physicallink.

Herein, a physical link is a BR/EDR physical link or a LE physical link,which allows enabling a baseband connection between wireless devices.BR/EDR physical links include BR/EDR active physical links and BR/EDRconnectionless slave broadcast physical links. LE physical links includeLE active physical links, LE advertising physical links, LE periodicphysical links, and LE isochronous physical links.

Preferably, the physical link PL1 is an active BR/EDR physical link or aLE isochronous physical link.

FIG. 8 illustrates a flowchart of method steps according to a fourthembodiment of the disclosure.

In this fourth embodiment, the audio data AD1 being received from thestreaming application 40 is packetized using the audio codecconfiguration and the sampling rate of the streaming application 40 intothe Bluetooth audio stream configured. Simultaneously or successively,audio data AD2 which corresponds to a second audio stream coming fromthe audio server 30 is packetized into said Bluetooth audio stream usingthe audio codec configuration and the sampling rate of the second audiostream.

As an alternative, the two audio streams use the same audio codecconfiguration and sampling rate. It is then possible to transmit thesetwo audio streams over a same Bluetooth communication link L1, as shown.

When AD1 and of AD2 are packetized into the same Bluetooth audio stream,they can be later unpacketized and decoded by the sink device 20. Inparticular, the unpacketizing and the decoding can be carried outsimultaneously or successively for each of AD1 and of AD2.

FIG. 9 illustrates method steps according to the fourth embodiment ofthe disclosure. In particular, these method steps allow transmitting twoaudio streams over a Bluetooth communication link.

During step S10, and as described previously, a Bluetooth link is openedor pre-established between the source device and the sink device.Preferably, this is carried out when the streaming application runningon the source device requests to open at least one audio stream. Theopening of an audio stream by the streaming application can include thesource device receiving an audio codec configuration and a sampling ratefrom the streaming application.

During step S41, said at least one Bluetooth audio stream is configuredor reconfigured with an audio codec configuration and a sampling rate ofthe streaming application 40.

During step S42, which is carried out either successively orsimultaneously with respect to step S41, at least one another Bluetoothaudio stream is configured or reconfigured with an audio codecconfiguration and a sampling rate of the audio server 30, or with theaudio codec configuration and the sampling rate of the streamingapplication.

During step S51, the source device 10 receives the audio stream from thestreaming application 40, called first audio stream. During step S52,which is carried out either successively or simultaneously with respectto step S51, the source device receives the audio stream from the audioserver 30, called second audio stream.

During step S61, the source device packetizes the first audio streaminto the Bluetooth audio stream which has been configured during stepS41 using the audio codec configuration and the sampling rate of thestreaming application.

During an optional step S62, which is carried out either successively orsimultaneously with respect to step S61, the source device packetizesthe second audio stream into said Bluetooth audio stream.

During step S70, the source device 10 transmits the Bluetooth audiostreams comprising the packetized first and second audio streams to thesink device 20.

As an alternative to step S70, steps S61 and S62 may be followed by twodistinct transmission steps S71 and S72 which are not represented. Insuch a situation, the first and second packetized audio streams can betransmitted through separate logical links.

FIG. 10 illustrates a Bluetooth communication link for carrying out thefourth embodiment of the disclosure.

As illustrated, two Bluetooth audio streams BTSTRM1 and BTSTRM2 aretransmitted from the source device 10 to the sink device 20 over asingle Bluetooth communication link.

In particular, the first Bluetooth audio stream BTSTRM1 comprises afirst contribution ASTRM1 and the second Bluetooth audio stream BTSTRM2comprises a second contribution ASTRM2, said first contribution ASTRM1being the audio stream provided by the streaming application 40 runningon the source device 10 and the second contribution ASTRM2 being theaudio stream provided by the audio server 30.

Preferably, the Bluetooth audio streams BTSTRM1 and BTSTRM2 are eachA2DP Bluetooth audio streams, said Bluetooth audio streams being enabledby one logical link LL1, such as an ACL-U logical link, carried by onelogical transport LT1, such as an ACL logical transport. The Bluetoothaudio streams BTSTRM1 and BTSTRM2, the logical link LL1 and the logicaltransport LT1 define a physical link PL1, preferably a BR/EDR activephysical link.

FIG. 11 illustrates a flowchart of method steps according to a fifthembodiment of the disclosure.

In particular, the method steps of the fifth embodiment are similar tothose of the fourth embodiment except that, in addition to the Bluetoothcommunication link L1, at least one another Bluetooth logical link LL2is open between the source device 10 and the sink device 20. This allowstransmitting one or more audio streams over two distinct Bluetoothlogical links.

For instance, said at least another link LL2 is opened during step S10when the streaming application 40 requests opening a stream.

FIG. 12 illustrates two Bluetooth communication links for carrying outthe fifth embodiment of the disclosure.

As illustrated, two Bluetooth audio streams BTSTRM1 and BTSTRM2 aretransmitted from the source device 10 to the sink device 20. The firstBluetooth audio stream BTSTRM1 comprises a first contribution ASTRM1,and the second Bluetooth audio stream BTSTRM2 comprises a secondcontribution ASTRM2. Again, said first contribution ASTRM1 is the audiostream provided by the streaming application 40 and said secondcontribution ASTRM2 is the audio stream provided by the audio server 30.

The Bluetooth audio stream BTSTRM1 is enabled by a logical link LL1,such as an ACL-U logical link, while the Bluetooth audio stream BTSTRM2is enabled by another logical link LL2, such as a LE-S logical link.

The logical link LL1 is carried by a logical transport LT1, such as anACL logical transport, while the logical link LL2 is carried by anotherlogical transport LT2, such as a LE connected isochronous logicaltransport.

The Bluetooth audio stream BTSTRM1, the logical link LL1 and the logicaltransport LT1 define a physical link PL1, which is preferably a BR/EDRactive physical link. The Bluetooth audio stream BTSTRM2, the logicallink LL2 and the logical transport LT2 define a physical link PL2, whichis preferably a LE isochronous physical link.

FIG. 13 illustrates a flowchart of method steps according to a sixthembodiment of the disclosure.

In particular, these method steps are similar to those of the first,second and third embodiments except that the packetizing of the audiodata AD1 and AD2 is carried out by wrapping said audio data in acontainer, such as an Ogg-container. This results in a physicalbitstream which can subsequently be packetized and transmitted over aBluetooth communication link established between the source device 10and the sink device 20.

After said container, or physical bitstream, is received by the sinkdevice 20, it is subsequently unpacketized and unwrapped. Subsequentdecoding steps can then be carried out, one decoding step being carriedout for the logical bitstream of the physical bitstream whichcorresponds to the streaming application, and another decoding stepbeing carried out for the logical bitstream of the physical bitstreamwhich corresponds to the audio server. The two decoding steps can becarried out separately or together as a single decoding step.

FIG. 14 illustrates method steps corresponding to the sixth embodimentof the disclosure.

Specifically, after receiving the first audio stream during step S51 andafter receiving the second audio stream during step S52, the two audiostreams are packetized into a container CT during a step S55, thenpacketized during a step S65, before eventually being transmitted duringa step S75 to the sink device 20.

FIG. 15 illustrates a Bluetooth communication link for carrying out thesixth embodiment of the disclosure.

Specifically, a Bluetooth audio stream BTSTRM1 is transmitted from thesource device 10 to the sink device 20, said Bluetooth audio streamBTSTRM1 comprising a first contribution ASTRM1 and a second contributionASTRM2. Said first contribution ASTRM1 is an audio stream provided bythe streaming application running on the source device 10 and saidsecond contribution ASTRM2 is an audio stream provided by an audioserver.

In the present case, the two contributions ASTRM1 and ASTRM2 areencapsulated in a container CT before being transmitted from the sourcedevice 10 to the sink device 20.

Again, the Bluetooth communication link defined by the audio streamBTSTRM1, the logical link LL1 and the logical transport LT1 can includeone or more physical links and defines the wireless communicationbetween the source device 10 and the sink device 20.

Again, and preferably, the Bluetooth audio stream BTSTRM1, the logicallink LL1 and the logical transport LT1 define a physical link PL1, suchas a BR/EDR physical link.

Advantageously, the container CT is here an Ogg-Vorbis container. WhileBluetooth standards merely allow packetizing audio data in a singleaudio stream, using an Ogg-Vorbis container allows having multiple audiostreams in a same packet. In other words, using Ogg-Vorbis containers,or Ogg stream containers, allows encapsulating one or more logicalbitstreams.

Moreover, this allows providing the sink device 20 the requiredinformation to properly separate the audio data back without relying ondecoding to find the corresponding packet boundaries. In this case, thecodec used to encode the audio data provided by the audio server 30should be compatible with the container CT.

Once encoded, a logical bitstream coming from the audio server can bewrapped into the container with the logical bitstream of the streamingapplication. Both logical bitstreams can then be sent within a samepacket to the sink device 20. Said sink device 20 can then unwrap thetwo logical bitstreams, decode them separately using their respectivecodecs, and carry out a mixing of the decoded result to provide a singlestream to be output.

FIG. 16 shows a device 1000 adapted for implementing a method accordingto an embodiment of the disclosure, and specifically, a method fortransmitting or for receiving an audio stream over a Bluetoothcommunication link when managing a plurality of multimedia devices.

In an embodiment, the device 1000 comprises a Bluetooth chip, which isintegrated in an electronic circuit or in any type of electronic device,such as the source device or the sink device.

As illustrated, the device 1000 comprises a storage space 1002, forexample a memory MEM including a random access memory 1002. The storagespace 1002 can also be a nonvolatile memory such as a ROM or a Flashmemory, and can provide a recording medium, said recording medium beingconfigured to store a computer program product.

The device 1000 further comprises a processing unit 1004 equipped forexample with a circuit which includes or is a processor PROC. Theprocessing unit 1004 can be controlled by a program, such as a computerprogram implementing the managing method as described herein withreference to any of the previous figures. The processing unit 1004 canstore instructions for performing the steps described with reference toany of the aforementioned embodiments.

The device 1000 may also comprise a database 1010 for storing data likeaudio data, an audio stream, a container or any bitstream. The database1010 can further store any information such as an audio codecconfiguration or a sampling rate.

The device 1000 further comprises an input interface 1006 and an outputinterface 1008, which are configured for establishing a communication toand from the multimedia device to external devices. For instance, theoutput interface 1008 can be a communication module enabling the device1000 to connect via Bluetooth and for exchanging data with other devicesvia Bluetooth. The communication module preferably includes a Bluetoothcommunication module.

Throughout this disclosure, the opening of a new audio stream wasprovided as an example of the point in various disclosed processes atwhich a source device received an audio codec configuration and asampling rate from a streaming application. The audio codecconfiguration and sampling rate being part of the information providedto the source device whilst that stream was being created. However,there are many ways in which the processes can involve receiving anaudio codec configuration and a sampling rate of an audio stream comingfrom a streaming application running on the source device. For example,the codec configuration and sampling rate can be received as part ofestablishing the communication link when the source and sink aresupporting an audio service (e.g., Advanced Audio Distribution Profileor A2DP in Bluetooth classic). In these approaches both the codec andthe sampling rate are negotiated when the audio service is configured.As another example, the codec configuration and sampling rate can bereceived as part of the reconfiguration of an audio service for analready established communication link between two devices. As anotherexample, the codec configuration and sampling rate can be providedthrough custom control or signaling messages in case the two devices areimplementing a custom service that is outside the scope of the Bluetoothstandard.

According to an embodiment, the Bluetooth chip is configured toimplement one or more of the steps that have been described in thepresent disclosure.

Herein, expressions such as “comprise”, “include”, “incorporate”,“contain”, “is” and “have” are to be construed in a non-exclusive mannerwhen interpreting the description and its associated claims, namelyconstrued to allow for other items or components which are notexplicitly defined also to be present. Reference to the singular is alsoto be construed to be a reference to the plural and vice versa.

While there has been illustrated and described embodiments of thepresent invention, it will be understood by those skilled in the artthat various other modifications may be made, and equivalents may besubstituted, without departing from the true scope of the presentinvention. Additionally, many modifications may be made to adapt aparticular situation to the teachings of embodiments of the presentinvention without departing from the scope of the invention.Furthermore, an embodiment of the present invention may not include allof the features described above. Therefore, it is intended that thepresent invention not be limited to the particular embodimentsdisclosed, but that the invention includes all embodiments fallingwithin the scope of the appended claims.

A person skilled in the art will readily appreciate that variousparameters disclosed in the description may be modified and that variousembodiments disclosed and/or claimed may be combined without departingfrom the scope of the invention.

What is claimed is:
 1. A method for transmitting an audio stream over aBluetooth communication link, the method being carried out by a sourcedevice and comprising: receiving an audio codec configuration and asampling rate of a first audio stream, said first audio stream comingfrom a streaming application running on the source device, and saidaudio codec configuration and said sampling rate being associated withan encoding format of the first audio stream; configuring, after receiptof the audio codec configuration and sampling rate of the first audiostream, a first Bluetooth audio stream between the source device and asink device using the received audio codec configuration and samplingrate; receiving the first audio stream from the streaming application;wrapping the received first audio stream into a container withoutmodifying the encoding format of the received first audio stream, andplacing the container into said first Bluetooth audio stream; andtransmitting the first Bluetooth audio stream to the sink device overthe Bluetooth communication link, the transmitted first Bluetooth audiostream comprising the received first audio stream.
 2. The methodaccording to claim 1, wherein the receiving of the first audio streamfrom the streaming application is carried out upon receipt of anunmodified bitstream from the streaming application.
 3. The methodaccording to claim 1, further comprising: receiving at least a secondaudio stream, said second audio stream being different from the firstaudio stream, from an audio server; and transmitting said receivedsecond audio stream to the sink device over the Bluetooth communicationlink.
 4. The method according to claim 3, wherein the first Bluetoothaudio stream is of a multi-contribution type, the method furthercomprising packetizing the received second audio stream into the firstBluetooth audio stream using the audio codec configuration and asampling rate of the second audio stream.
 5. The method according toclaim 3, further comprising wrapping the received second audio streaminto the container.
 6. The method according to claim 5, wherein thecontainer is an Ogg-Vorbis container.
 7. The method according to claim5, wherein at least one of the first audio stream and the second audiostream is a Vorbis encoded stream.
 8. The method according to claim 3,further comprising: packetizing the received second audio stream into asecond Bluetooth audio stream, said second Bluetooth audio stream beingdistinct from the first Bluetooth audio stream, and transmitting saidsecond Bluetooth audio stream to the sink device over the Bluetoothcommunication link, the second Bluetooth audio stream being multiplexedwith the first Bluetooth audio stream.
 9. The method according to claim8, wherein at least one of the first Bluetooth audio stream and thesecond Bluetooth audio stream is transmitted over a BR/EDR link of theBluetooth communication link.
 10. The method according to claim 8,wherein the second Bluetooth audio stream is transmitted over a BLE linkof the Bluetooth communication link.
 11. The method of claim 1, whereinthe transmitting of the first Bluetooth audio stream is performed upon asuccessful negotiation, with the sink device, of the audio codecconfiguration and of the sampling rate.
 12. A non-transitory,computer-readable medium having stored thereon computer programinstructions loadable into a computing device and adapted to, whenloaded into and executed by said computing device, cause the computingdevice to perform operations comprising: receiving an audio codecconfiguration and a sampling rate of a first audio stream, said firstaudio stream coming from a streaming application running on a sourcedevice, and said audio codec configuration and said sampling rate beingassociated with an encoding format of the first audio stream;configuring, after receipt of the audio codec configuration and samplingrate of the first audio stream, a first Bluetooth audio stream betweenthe source device and a sink device using the received audio codecconfiguration and sampling rate; receiving the first audio stream fromthe streaming application; wrapping the received first audio stream intoa container without modifying the encoding format of the received firstaudio stream, and placing the container into said first Bluetooth audiostream; and transmitting the first Bluetooth audio stream to the sinkdevice over a Bluetooth communication link, the transmitted firstBluetooth audio stream comprising the received first audio stream. 13.The non-transitory, computer-readable medium according to claim 12,wherein the receiving of the first audio stream from the streamingapplication is carried out upon receipt of an unmodified bitstream fromthe streaming application.
 14. The non-transitory, computer-readablemedium according to claim 12, the operations further comprising:receiving at least a second audio stream, said second audio stream beingdifferent from the first audio stream, from an audio server; andtransmitting said received second audio stream to the sink device overthe Bluetooth communication link.
 15. The non-transitory,computer-readable medium according to claim 14, wherein the firstBluetooth audio stream is of a multi-contribution type, the operationsfurther comprising packetizing the received second audio stream into thefirst Bluetooth audio stream using the audio codec configuration and asampling rate of the second audio stream.
 16. The non-transitory,computer-readable medium according to claim 14, the operations furthercomprising wrapping the received second audio stream into a container,said container being placed into the first Bluetooth audio stream. 17.The non-transitory, computer-readable medium according to claim 16,wherein at least one of the first audio stream and the second audiostream is a Vorbis encoded stream.
 18. The non-transitory,computer-readable medium according to claim 14, the operations furthercomprising: packetizing the received second audio stream into a secondBluetooth audio stream, said second Bluetooth audio stream beingdistinct from the first Bluetooth audio stream, and transmitting saidsecond Bluetooth audio stream to the sink device over the Bluetoothcommunication link, the second Bluetooth audio stream being multiplexedwith the first Bluetooth audio stream.
 19. The non-transitory,computer-readable medium of claim 12, wherein the transmitting of thefirst Bluetooth audio stream is performed upon a successful negotiation,with the sink device, of the audio codec configuration and of thesampling rate.
 20. A source device for transmitting an audio stream overa Bluetooth communication link, said source device being configured to:receive an audio codec configuration and a sampling rate of a firstaudio stream of a streaming application running on the source device,said audio codec configuration and said sampling rate being associatedwith an encoding format of the first audio stream; configure, afterreceipt of the audio codec configuration and sampling rate of the firstaudio stream, a first Bluetooth audio stream between the source deviceand a sink device, using the received audio codec configuration andsampling rate; receive the first audio stream from the streamingapplication; wrap the received audio stream into a container withoutmodifying the encoding format of the received first audio stream, andplacing the container into said first Bluetooth audio stream; andtransmit the first Bluetooth audio stream to the sink device, thetransmitted first Bluetooth audio stream comprising the received firstaudio stream.